formalTOILET a toilet or the room a toilet is in 厕所,洗手间
Examples from the Corpus
lavatory• The public lavatories are situated on the other side of the beach.• Even the lavatory was luxurious, with a marble interior and soft, white hand towels.
Originlavatory
(1300-1400)Medieval Latinlavatorium“bowl for washing in”, from Latinlavare“to wash”